Process and a device for surgical treatment of rectal and haemorrhoidal prolapse

ABSTRACT

A process for surgical operations on a rectal/haemorrhoidal prolapse comprises stages of realising, in the anal canal, at least a first circular stitching at a first portion of a haemorrhoidal prolapse; realising at least a second circular stitching in a second portion of the haemorrhoidal prolapse, and nearing the first circular stitching and the second circular stitching in order to create a constriction of the haemorrhoidal prolapse. The invention also relates to a device, preferably for actuating the process, which comprises a hollow divaricator ( 17 ) having a prevalent development direction along a longitudinal axis (Z) and being insertable in a patient&#39;s anal orifice. The device further exhibits a window ( 29 ) defining an operational area and creating a communication between a cavity ( 17   b ) internal of the divaricator ( 17 ) and a portion of haemorrhoidal prolapse. The device further comprises means for opening and closing ( 31 ) the window ( 29 ).

TECHNICAL FIELD

The invention relates to a process and a device for surgical treatmentof rectal and haemorrhoidal prolapse.

The invention applies to the field of surgical operations associated toproctological pathologies, in particular aimed at treatment and/orreduction of rectal and haemorrhoidal prolapse.

BACKGROUND ART

As is well-known, the development of haemorrhoidal diseases is caused bypathological alterations in the cavities of the anal canal, which areformed by vascular spaces, arterio-venous shunts and saccular venousstructures constituting the internal haemorrhoidal plexus. In moredetail, the internal haemorrhoidal plexi are haematic spaces of acalibre of a few millimetres delimited by a venous or capillaryendothelium internal of a connective tissue, covered by rectal mucousmembrane. These structures are supported by anchoring fibres to theinternal sphincter, which form the Treitz or Parks is ligaments.

The cavities receive arterial flow only from terminal branches of theupper rectal artery, a peculiarity which has led to the treatmentsadopted for the most recent treatment programmes.

The development of surgical techniques in this field is in continualevolution, as where possible it is sought to render these operations aslittle traumatic as possible, especially in the light of the prior art,which often leads to grave risks and complications for patients who aresubjected to this type of operation.

The principal surgical techniques, especially with reference to thepast, were based on the removal of tissue, i.e. the surgical removal ofthe portions of rectal mucous membrane affected by the pathology.

A procedure of this type includes the removal of haemorrhoidal prolapsesat the same time as suturing the interested areas.

A procedure of this type is described in detail in document WO 01/21060,which illustrates an accessory kit for trans-anal operations, and aprocedure for use thereof.

In detail, this procedure involves acting on the mucous wall of therectal wall, especially on the portion of mucous wall interested by thehaemorrhoidal prolapse, by providing a ring or circumferentialstructure, similar to a tobacco pouch. This is done by circularstitching a suture thread several times until it interests the wholeprolapse along the circumferential development of the rectal ampoule,realising an annular extrusion which tends towards the inside of therectal ampoule.

Subsequently the annular extrusion thus realised is resected,simultaneously suturing the remaining bunched edges of the mucous wall.

A device used for realising this procedure comprises a semi-cylindricalbody, coupled to a handle that can be gripped and inserted into the analorifice of a patient, for example using an anatomical cone-shapedintroducer. The semicylindrical body exhibits an opening at a front endthereof, which intercepts a part of the haemorrhoidal prolapse andenables extrusion thereof internally of the body. The device furthercomprises a mechanical suturing device, used after the semicylindricalbody, for cutting the annular extrusion by means of a cylindrical blade,and suturing the closed-to edges of the remaining part of the mucousmembrane by firing metal staples internally of the edges.

A procedure of this type is necessarily very traumatic.

In particular, though giving good results and on the whole preventingrelapses, the procedure causes considerable post-operative pain, andrequires admission of the patient to hospital and can also be the causeof greater post-operative and intra-operative risks.

Different intervention techniques have also been researched, known aspara-surgical techniques, aimed at obviating the grave drawbacks oftraditional surgery. These techniques comprise, for example, elasticligation of the haemorrhoidal tissue, compressing a haemorrhoid at itspoint of attachment to the mucous wall of the rectal canal by elasticligature, and causing the is physiological collapse thereof withoutrecourse to excision of the haemorrhoidal tissue. A further example ofpara-surgical technique is sclerotherapy, which causes necrosis of theinterested part by injection of a sclerosing solution.

Further examples of para-surgical techniques comprise infra-redcoagulation, cryotherapy or laser therapy.

Some of these para-surgical treatments adopt a device of the typedescribed in patent WO 2004/064624. This device comprises a cylindricalbody functioning as a divaricator, exhibiting a grip and, in the lateralposition, an opening for intercepting and observing a portion ofhaemorrhoidal prolapse. In proximity of the opening, the body comprisesa seating for housing a probe (in particular, an ultrasound probe) ableto detect vicinity to a blood vessel in order to enable a correct directintervention on the zone actually interested by the haemorrhoidalprolapse, even where there is a poor visibility and/or accessibility tothe area. The device further comprises means for illuminating,associable to the grip, for illuminating the area interested by theintervention and if necessary for lighting up the inside of thecylindrical body. In particular, a device of the above-described type isused for creating the surgical occlusion in the terminal part of theupper rectal artery, which involves the haemorrhoidal prolapse, by aligature in the area surrounding the artery (with the use of a curvedsuturing needle) followed by a pinching of the area causing collapse dueto interruption of blood flow.

However, this technique cannot by itself reduce, over a short timeperiod, the presence of the haemorrhoidal prolapse internally of theanal canal.

Therefore a technical aim of the present invention is to provide aprocess and a device for surgical operations on a rectal and ahaemorrhoidal prolapse which obviates the above-cited drawbacks.

A fundamental aim of the invention is to provide a process and a devicefor surgical operations on a rectal and a haemorrhoidal prolapse whichreduces haemorrhoidal prolapses internally of the rectal canal in ashort time.

A further aim of the invention is to provide a process and a device forsurgical operations on a rectal and haemorrhoidal prolapse which is ableto reduce post-operative complications and post-operative pain.

A further important aim of the invention is to provide a process and adevice for surgical operations on a rectal and haemorrhoidal prolapsewhich limits a need for using anaesthetics on the patient, or which inany case localises the need for anaesthesia as far as possible.

The specified aims and others besides are substantially attained by aprocess and device for surgical operations on a rectal and haemorrhoidalprolapse according to what is set out in the appended claims.

DISCLOSURE OF INVENTION

A description will now be made, by way of non-exclusive and non-limitingexample, of a preferred embodiment of a process and a device forsurgical operations on a rectal and haemorrhoidal prolapse, withreference to the accompanying figures of the drawings, in which:

FIG. 1 is a schematic view in longitudinal section of an anal canal;

FIG. 2 is a lateral view of a device of the invention;

FIG. 3 is a perspective view of a first portion of the device of FIG. 2;

FIG. 4 is a plan view of a first portion of the device of FIG. 2;

FIG. 5 is a section view of a first portion of the device of FIG. 2;

FIG. 6 is a lateral view of a second portion of the device of FIG. 2;

FIG. 7 is a perspective view of a second portion of the device of FIG.2.

A preferred embodiment of a process and a device for surgical operationson a rectal and haemorrhoidal prolapse of the invention comprises thefollowing is stages:

-   -   realising at least a first circular stitching 1 at a position of        a rectal-haemorrhoidal prolapse 2 by means of, for example, a        suture thread 6;    -   realising at least a second circular stitching 4 at the same        position i.e. at the haemorrhoidal prolapse 2    -   nearing the first 1 and second 4 circular stitchings in order to        create a constriction of the haemorrhoidal prolapse 2.

Advantageously the first circular stitching 1 and the second circularstitching 4 are made respectively at a first portion 2 a and a secondportion 2 b of the haemorrhoidal prolapse 2, which is localised, in FIG.1, in proximity of the end of terminal tract of the rectum 5 anddevelops in a prevalent direction X. Further, the first portion 2 a ofthe prolapse 2 is deeper inside the rectum 5 than the second portion 2b. This gives special advantages, as will better emerge in the followingdescription.

The circular stitchings are made using various suturing elements.

In the embodiment of FIG. 1, a thread 6 is preferred and illustrated,which will be termed hereinafter the suturing thread 6.

The suturing thread 6 is wound several times about the haemorrhoidalprolapse 2, which projects from a wall 7 of the rectum 5 towards theinside of the rectum 5 itself and in the direction of the anal orifice 8of the rectum 5. In the schematic illustration of FIG. 1, the wire 6 ispartially inserted internally of the tissues which constitute the wall 7of the rectum 5, and in particular internally of the tissues definingthe haemorrhoidal prolapse 2. The insertion of the thread 6 in thetissues is preferably done using an acuminate body, for example aneedle, not illustrated as of known type.

Preferably the stage of realisation of the first circular stitching 1 isdone by inserting a first end 9 of the thread 6 into the first portion 2a of the haemorrhoidal prolapse 2. The realisation of the secondcircular stitching 4, preferably using the same suture thread 6, is donein the same way, by inserting the first end 9 of the thread 6 into thesecond portion 2 b of the haemorrhoidal prolapse 2. The thread 6, inthis configuration and as in FIG. 1, exhibits the first end 9 at theposition of the second circular stitching 4, while it exhibits a freesecond end 10 at the position of the first circular stitching 1. Theabove-described process has the curved needle at the first end of thethread 6.

The stage of realising the first circular stitching 1 advantageouslyalso comprises a stage of realising further circular stitchings 11. Thefurther circular stitchings 11 are realised at a third portion 12 of thehaemorrhoidal prolapse 2, situated between the first portion 2 a and thesecond portion 2 b. FIG. 1 illustrates two further circular stitchings11, located in intermediate positions between the first circularstitching 1 and the second circular stitching 4. The circular stitchings1, 4, 11 are preferably realised using a single suture thread 6.

Furthermore, each circular stitching 1, 4, 11 of the thread 6advantageously interests a terminal branch of a rectal artery 13associated to the haemorrhoidal prolapse 2, with the result that theterminal branch can subsequently be pinched, following a technique whichwill be described herein below.

In particular, the curved needle is handled and guided to complete atrack, internally of the tissues of the haemorrhoidal prolapse 2, whichcircumscribes the terminal branch of the rectal artery 13 so that at theend, when the curved needle re-emerges from the tissues, a loop isgenerated, internally of which the above-mentioned rectal artery 13terminal branch is contained. Thus each stage of realisation of acircular stitching 1,4, 11, comprises a stage of realising at least aloop linked to the terminal branch of the rectal artery 13 interested bythe proctological pathology.

In the preferred embodiment of the process of the invention andillustrated in FIG. 1, each loop is contained in a plane which isperpendicular to the prevalent development direction X of thehaemorrhoidal prolapse 2. This is advantageous as each stage of therealisation of a circular stitching 1, 4, 11 also comprises a stage ofpinching the respective circular stitching 1,4, 11. Each single loop,once completed, is subjected to a preferably manual drawing action onthe suture thread 6. This is much simplified by the lie of the singleloops as described above, as an exclusively transversal constriction isrealised with respect to the development of the rectal artery 13,without causing alterations in an axial direction.

The drawing of the suture 6 has the aim of realising a constriction of aportion of the haemorrhoidal prolapse 2 (and therefore a respectivetract of the rectal artery 13) associated to a single loop, and causesinterruption of blood flow in that tract, leading to collapse thereof.

The stages of creating the circular stitchings 1, 4, 11 are preferablyperformed by realising the circular stitchings 1, 4, 11 in substantiallyoverlapped positions along the prevalent development direction X of thehaemorrhoidal prolapse 2. This results in an ordered succession of loopsaccording to the configuration of FIG. 1, in which a single loop“packet” orderedly surrounds the haemorrhoidal prolapse 2.

Subsequently to the completion of the circular stitchings 1, 4, 11stages, advantageously there is a stage of reciprocal nearing of thefirst circular stitching 1 and the second circular stitching 4 in orderto realise a constriction of the haemorrhoidal prolapse 2 also along itsprevalent development direction X. In this way a considerable reductionof the overall size of the haemorrhoidal prolapse 2 internally of therectum 5 is achieved.

The stage of nearing the circular stitchings 1, 4 is preferably done viaa stage of knotting the suture thread 6. The knotting stage comprises astage of realising one or more consecutive knots, which stabilise apreceding nearing action of the circular stitchings 1, 4.

Further, the process of the invention can advantageously comprise astage of creating a further circular stitching, in particular the “basiccircular stitching”, partially illustrated in FIG. 1 and denoted by 14,which serves as a reference for the final drawing-in of the thread 6.

This stage, preferably performed before realising the first circularstitching 1, is done by creating at least a loop in a portion of wall ofthe rectum 5 which is not involved in the haemorrhoidal prolapse 2. Therealisation of the basic circular stitching 14 has the aim of definingan anchor for the subsequent stage of nearing the circular stitchings 1,4, as will be better explained herein below.

It is further preferable that the basic circular stitching 14 berealised using the suture thread 6 used for realising the circularstitchings 1, 4, 11. The basic circular stitching 14 is further realisedpreferably in a portion of the rectum 5 situated more deeply than thehaemorrhoidal prolapse 2 with respect to the anal orifice 8, and thus ina higher position as in FIG. 1. The basic circular stitching 14 is thussituated more deeply than the first circular stitching 1 too, by virtueof what is stated herein above with reference to the directing of thefirst circular stitching 1 and the second circular stitching 4.

In detail, the second end 10 of the suture thread 6, localised at thefirst circular stitching 1 and therefore at the basic circular stitching14 position, is partially folded in order to define a slot, denoted by15 in FIG. 1 in an initial stage of formation. The first end 9 of thesuture thread 6 can be inserted is internally of the slot 15 and thestage of nearing the circular stitchings 1, 4 can begin, by drawing thesuture thread 6; then the knotting stage can be begun, which defines astable nearing position of the circular stitchings.

The above stages, which constrict the haemorrhoidal prolapse 2, alsoraise the haemorrhoidal prolapse 2 in the direction of the basiccircular stitching 14 and deep into the anal canal 5 (as can be seen onthe area on the right of FIG. 1 which illustrates the constriction andraising of a treated haemorrhoidal prolapse 2). This gives the advantageof distancing the haemorrhoidal prolapse 2 from the anal orifice 8,reducing its size internally of the rectum 5 and also correctlyrepositioning the anal padding above the pain threshold line.

The basic circular stitching 14 therefore functions as a point ofreference, towards which the haemorrhoidal prolapse 2 is pulled and thenlinked with the circular stitchings 1, 4, 11 so as to generate at thesame time the constriction of the haemorrhoidal prolapse 2 and thereduction of the size of the haemorrhoidal prolapse 2 internally of therectum 5.

The process of the invention is applicable to operations forhaemorrhoidal prolapses of various types and entities, and can be summedup by being described as including the creation of a plurality ofcircular stitchings able to link the haemorrhoidal prolapse and theassociated rectal artery, preferably by means of a single suture threadand the realisation of at least one basic circular stitching, made at aportion of the rectal canal wall which is not lo interested byhaemorrhoidal pathologies.

There follows a description of a device for surgical operations on arectal-haemorrhoidal prolapse, preferably but not exclusively forrealising the above-described process.

The device, denoted by 16, comprises a hollow divaricator 17, exhibitinga cylindrical central portion 17 a internally affording a cavity 17 awhich is the intervention zone of the device. The central portion 17 ais connected to a closed front portion 17 c having a preferably taperedcone shape to enable it to be inserted internally of the anal orifice ofa patient, reducing to a minimum the patient's traumatic experience. Thedivaricator 17 further comprises a truncoconical posterior portion 17 d,larger transversally in order to define the maximum penetration of thedivaricator 17 internally of the anal orifice. The posterior portion 17d is also hollow, to afford access to the cavity 17 b by an externaloperator during an operation, at a posterior end 17 e with reference toa penetration direction of the divaricator 17 internally of the analorifice. The device 16 further comprises a first half-shell 18, firmlyconstrained to the posterior portion 17 c of the divaricator 17 to forma handle portion of the device 16. The first half-shell 18 is coupled,preferably by male-female jointed parts 19, 20, to a second half-shell21, which completes the formation of the handle of the device 16. Inthis configuration, the handle defines, in a portion comprised betweenthe two half-shells 18, 21, a first seating 22 for housing means forilluminating 23.

The means for illuminating 23 are preferably made with an optic fibre24.

The optic fibre 24 is, for example, inserted at a free end of thehandle, pushed internally of the first seating 22 up until it reaches anoperative position in which it emits a light which can reach inside thedivaricator 17 in order to illuminate the work area(retro-illumination).

The divaricator 17 exhibits, preferably in a lateral portion thereof, awindow 29 which defines an area of operation and which establishes acommunication between the cavity 17 b, and therefore the means foroperating positioned internally of cavity 17 b, and a wall of therectum, when the device 16 is inserted. The window 29 enables easyaccess to a haemorrhoidal prolapse is present on the rectum wall.

The window 29 exhibits at least a first portion 29 a, between thecentral portion 17 a and the front portion 17 c. In the preferredembodiment illustrated in FIGS. 2 and 3, the first portion 29 a of thewindow 29 extends prevalently in a transversal direction to alongitudinal axis Z, along which longitudinal axis Z the divaricator 17prevalently develops. In the illustrated embodiment, the first portion29 a of the window 29 is rectangular.

Preferably the front portion 17 c of the divaricator 17 exhibits, inproximity of the first portion 29 a of the window 29, a bevel 30 forfurther facilitating penetration of the divaricator 17 internally of theanal orifice, while at the same time the bevel 30 receives thehaemorrhoidal prolapse in the window 29.

The window 29 advantageously has a variable extension, preferably in aparallel direction to the longitudinal axis Z of the divaricator 17.This extensibility is achieved by means for opening and closing 31 thewindow 29, which means will be better explained herein below.

The window 29 advantageously exhibits a second portion 29 b, preferablyadjacent to the first portion 29 a. In the preferred embodiment, thefirst portion 29 a and the second portion 29 b are in communication, andthus constitute a single window 29. Further, the second portion 29 b ofthe window 29 develops along the longitudinal axis Z of the divaricator17 and extends preferably from the first portion 29 a up to theposterior end 17 e of the divaricator 17.

The second portion 29 b can have any transversal size, preferably lessthan or equal to the transversal size of the first portion 29 a.

The means for opening and closing 31 the window are preferably realisedusing a mobile wall 32. The mobile wall 32 is slidably housed in thesecond portion 29 b of the window 29, for example by means of slidingguides 32 a, and can take on a plurality of operative positions betweena closed position, in which it entirely obstructs the second portion 29b of the window, leaving accessible only the first portion 29 a, and anopen position, in which is completely discovers the second portion 29 bof the window 29, which is thus entirely open and accessible from theoutside. The mobile wall 32 is moved between the closed and openpositions by a sliding motion in the direction of the posterior end 17 eof the divaricator 17. The increase in extension of the window in thelongitudinal direction as described above is advantageous especiallywhen performing ligature operations on the rectal artery is stitched, ina haemorrhoidal pathology.

In a preferred embodiment, illustrated in the accompanying figures ofthe drawings, the mobile wall 32 is associated only to the secondportion 29 b of the window 29, while the first portion 29 a isaccessible from the outside even when the mobile wall 32 is in theclosed position.

The mobile wall 32 can further exhibit dedicated means for gripping sothat the operator has an easy grip thereon. In the preferred andillustrated embodiment, however, the mobile wall 32 is counter-shaped tothe second portion 29 b of the window 29 with which it engages, so thatin the closed position there is no projection of the mobile wall 32 withrespect to the normal surface progression of the divaricator 17.

The device 16 also comprises sensors, not illustrated, for detecting thepulsation of a vein or artery, in particular for detecting the vicinityof a rectal artery. The sensors are preferably an ultrasound probe, andcan advantageously be housed on the mobile wall 32, preferablyremovably, so as continuously to monitor the vicinity of the rectalartery even during the sliding motion of the mobile wall 32.

For housing the sensors the mobile wall 32 exhibits a dedicated housing33 is facing towards an outside of the mobile wall 32 and therefore thedivaricator 17, by means of an external terminal aperture 33 a affordedon the mobile wall 32. The external terminal opening 33 a, which placesthe housing 33 in communication with the outside of the divaricator 17,facilitates detection of the rectal artery by the sensors, bringing themup to the wall of the rectum and placing them in direct contact with thehaemorrhoidal prolapse, so that they can detect the proximity of theartery by registering the associated blood flow. The housing 33 ispreferably also in communication with the cavity 17 b of the divaricator17 to enable introduction of the sensors internally of the housing 33through the posterior end 17 e of the divaricator 17.

Means for guiding 34 are housed internally of the cavity 17 b, whichmeans for guiding are fixed to the divaricator 17 and destined to guidethe means for operating during use, i.e. during the operating stage. Inmore detail, the means for guiding 34 comprise a holed support 35,preferably positioned in proximity of the first portion 29 a of thewindow 29. Further, the holed support 35 is fixed in a non-centredposition in proximity of the first portion 29 a of the window 29.Further, the holed support 35 is fixed in a non-centred position withrespect to the longitudinal axis Z of the divaricator 17, in particulartowards the window 29. This is very useful for the arterial ligatureoperations, in which a curved needle gripped by a needle holder is madeto describe a circular trajectory so that the needle, partially exitingfrom the divaricator 17 through the window 29, links the interestedhaemorrhoidal artery, previously detected by the ultrasound probe. Thecircular trajectory is obtained by causing the needle holder to rotate,while a front end thereof is housed internally of the holed support 35.

Externally the divaricator 17 can exhibit, at least on the centralportion 17 a thereof, one or more easily visible calibration marks 36,which can be for is example a plurality of reliefs, to give an intuitiveindication of the depth of penetration of the divaricator 17 into theanal orifice in real time.

The invention offers important advantages.

Primarily, the described process rapidly reduces the haemorrhoidalprolapse, preventing the need for painful surgical operations.

Further, the process involves less need for anaesthesia in comparison totraditional treatments.

Among the advantages of the process, first and foremost is the excellentresults it obtains with haemorrhoidal pathologies, while preserving thevascular padding which is important for questions of continence.

A further advantage is given by the fact that the process, thanks to theanchoring of the haemorrhoidal prolapse to the basic circular stitching,enables repositioning of the anal padding above the pain threshold line,thus eliminating the haemorrhoidal prolapse.

Regarding the described device, an important advantage is given by thepresence of the detractable mobile wall, which facilitates modificationof the area of operation, preferably in a case of arterial ligatureoperations, without having even to partially extract the divaricator,which is a particularly laborious task for the surgeon.

Further, the fixing of the sensor on the mobile wall enables acontinuous checking on the proximity of the interested rectal artery,without having to move the device if not strictly necessary.

Finally, the special geometry of the mobile wall does not include anyprojecting element able to cause discomfort or pain to the patient;indeed, the regular and anatomical shape of the wall satisfies therequirement for a low level of patient trauma.

1. A process for surgical operations on a rectal and haemorrhoidalprolapse, comprising a stage of: realising at least a first circularstitching (1) in a rectum of a patient, the first circular stitching (1)being at a first portion (2 a) of a haemorrhoidal prolapse (2); whereinthe process further comprises stages of: realising at least a secondcircular stitching (4) in a second portion (2 b) of the haemorrhoidalprolapse (2); nearing the first circular stitching (1) and the secondcircular stitching (4) in order to create a constriction of thehaemorrhoidal prolapse (2).
 2. The process of claim 1, wherein itcomprises a stage of realising further circular stitchings (11) atportions of the haemorrhoidal prolapse (2) comprised between the firstportion (2 a) and the second portion (2 b).
 3. The procets of claim 1,wherein the stages of realising the circular stitchings (1,4) compriseat least a loop contained in a perpendicular plane to a prevalentdevelopment direction (X) of the haemorrhoidal prolapse (2).
 4. Theprocess of claim 1 wherein the stages of realising the circularstitchings (1,4) are performed by realising the circular stitchings(1,4) overlapping one another along a prevalent development direction(X) of the haemorrhoidal prolapse (2).
 5. The process of claim 1,wherein the circular stitchings (1, 4) are realised using a singlesuture thread (6).
 6. The process of claim 1, wherein before arealisation stage of at least a first circular stitching (1), there is astage of realising at least a basic circular stitching (14) in a portionof rectal wall which is not interested by the haemorrhoidal prolapse(2), in order to define an anchoring for the neared circular stitchings(1, 4).
 7. The process of claim 6, wherein the basic circular stitching(14) is realised in a portion of the rectum (5) which is situated moredeeply with respect to the anal orifice (8) than the haemorrhoidalprolapse (2).
 8. The process of claim 5, wherein the stage of nearingthe circular stitchings (1, 4) comprises a stage of knotting the suturethread (6) in order to define a stable neared position of the circularstitchings (1, 4).
 9. The process of claim 1, wherein each stage ofrealising a circular stitching (1, 4) comprises a stage of drawing-in ofthe circular stitching (1, 4)
 10. The process of claim 8, wherein thesuture thread (6) exhibits a first end (9) associated to the secondcircular stitching (4), the stage of knotting the suture thread (6)comprising a stage of inserting the first end (9) of the suture thread(6) internally of the basic circular stitching (14).
 11. The process ofclaim 10, wherein the stage of knotting the suture thread (6) comprisesa stage of raising the circular stitchings (1, 4) in a direction towardsthe basic circular stitching (14). 12-24. (canceled)